Electro-osmotic flows inside triangular microchannels

31st UIT (Italian Union of Thermo-fluid-dynamics) Heat Transfer Conference 2013

Vocale, P.^1 ; Geri, M.^2 ; Morini, G.L.^2 ; Spiga, M.^1

Department of Industrial Engineering, University of Parma, Parco Area delle Scienze 181/A, 43124 Parma, Italy^1

DIN, Alma Mater Studiorum Università di Bologna, Viale Risorgimento 2, 40136 Bologna, Italy^2

关键词: Electric double layer;    Electroosmotic flow;    Elliptical cross section;    Governing equations;    Non-dimensional parameters;    Numerical investigations;    Triangular microchannels;    Volumetric flow rate;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/501/1/012026/pdf
DOI  :  10.1088/1742-6596/501/1/012026

来源: IOP

【 摘 要 】

This work presents a numerical investigation of both pure electro-osmotic and combined electro-osmotic/pressure-driven flows inside triangular microchannels. A finite element analysis has been adopted to solve the governing equations for the electric potential and the velocity field, accounting for a finite thickness of the electric double layer. The influence of non-dimensional parameters such as the aspect ratio of the cross-section, the electrokinetic diameter and the ratio of the pressure force to the electric force on the flow behavior has been investigated. Numerical results point out that the velocity field is significantly influenced by the aspect ratio of the cross section and the electrokinetic diameter. More specifically, the aspect ratio plays an important role in determining the maximum volumetric flow rate, while the electrokinetic diameter is crucial to establishing the range of pressures that may be sustained by the electro-osmotic flow. Numerical results are also compared with two correlations available in the literature which enable to assess the volumetric flow rate and the pressure head for microchannels featuring a rectangular, a trapezoidal or an elliptical cross-section.